Add keystone-config tag to SP/IDP setup task

Ensure the Keystone federation SP/IDP post-configuration runs when
executing by the keystone-config tag.

Change-Id: I9e1e69b84207b94d423d44e4b2b39da612db627f
Signed-off-by: Dmitriy Chubinidze <dcu995@gmail.com>

playbooks/keystone.yml

@@ -234,6 +234,8 @@
   hosts: keystone_all
   gather_facts: false
   user: root
+  tags:
+    - keystone-config
   environment: "{{ deployment_environment_variables | default({}) }}"
   tasks:
     - name: Setup installation variables